The Valve,safety Relief, cataloged under National Stock Number 4820-01-198-2743, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Swagelok Co. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-198-2743 |
| Primary Part Number | SS-4R3A-C |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Swagelok Co |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | ANGLE |
| Operating Pressure | 6000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +750.0 TO 1500.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 250.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Bonnet Attachment Method | THREADED |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL COMP 316 BODY |
| Thread Series Designator | UNF ALL ENDS |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 4820-01-198-2743 is a Valve,safety Relief, manufactured by Swagelok Co, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-198-2743 has 2 manufacturer part numbers on file: SS-4R3A-C (South London Valve & Fitting Company Ltd T/a Swagelok London), SS-4R3A-C (Swagelok Co).
Key specifications for SS-4R3A-C: Flow Control Device: POPPET; Connection Style: PLAIN (TUBE) ALL ENDS; Connection Type: THREADED EXTERNAL TUBE ALL ENDS; Style Designator: ANGLE. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.